Muscular system Flashcards
1
Q
Explain the location, function and description of skeletal muscle.
A
- Location= Attached to bone
- Function= Voluntary movement
- Description= Striated, multinucleate (more than one nucleus)
2
Q
Explain the location, function and description of cardiac muscle.
A
- Location= Walls of the heart
- Function= In-voluntary control, auto-rhythmic
- Description= Striated, uninucleate cells interlock at intercalated discs, single nucleus
3
Q
Explain the location, function and description of smooth muscles.
A
- Location= Walls of hollow organs
- Function= Involuntary, auto rhythmic, propels substances along internal passageways.
- Description= non-striated, cells arrange in a sheet structure, single nucleated
4
Q
What are the functions of muscle?
A
- Movement
- Posture
- Regulating organ volume
- Moving substances in the body= Cardiac muscle (heart), smooth muscle (peristalsis), skeletal muscle (lymph / blood)
- Heat production
5
Q
What are the different characteristics of muscle?
A
- Excitability= ability to respond to a stimulus
- Contractability= ability to contract when stimulated
- Extensibility= ability to be stretched/ extended
- Elasticity= ability to return to its original form after being stretched
6
Q
When does movement occur?
A
- When a muscle contract.
- Movement results from several muscles working together
- Most skeletal muscles are arranged in opposing pairs
= Antagonistic Pairs
7
Q
Muscles are arranged in opposing pairs, what are these called?
A
- Antagonistic pairs.
- Agonist= contracts to cause an action
- Antagonist= stretches and yields to action of the agonist
- Synergist= contracts to stabilise intermediate joints
- Fixator= stabilises origin of agonist
8
Q
What are muscle made up of?
A
- Bundles of muscle fibres called fascicles. These muscles and fibres are held together by sheets of connective tissue.
9
Q
What are the sheets of connective tissue found in muscle?
A
- Epimysium= surrounds whole muscle
- Perimysium= surrounds bundles of fibres (fascicles).
- Endomysium= surrounds individual muscle fibres
10
Q
What are the different contractile proteins?
A
- Actin and myosin are the contractile proteins.
- Troponin and tropomyosin are contraction inhibiting proteins.
11
Q
What is ATP?
A
- Produces energy for muscles.
- It is produced through different metabolic pathways: Creatine phosphate, anaerobic respiration and aerobic respiration.
12
Q
What does anaerobic respiration do?
A
- Provides ATP for short, moderate durations of activity (60 secs or slightly more). It does not require O2 and has two stages: Glycolysis and lactic acid formation.
- So, breakdown of glucose into pyruvic acid (through glycolysis). It produces 2 ATP molecules per breakdown of glucose molecule. Pyruvate is then converted to lactic acid in absence of O2.
13
Q
What does creatine phosphate do?
A
- Provides ATP for first few seconds of high intensity activity.
- Creatine phosphate donates a phosphate group to ADP from ATP, it is catalysed by the enzyme creatine.
- The reaction= creatine phosphate + ADP= creatine + ATP
14
Q
What does aerobic respiration do?
A
- Provides ATP for prolonged activities: several mins- hours.
- It requires O2 and has three stages: glycolysis, kreb’s cycle, oxidative phosphorylation.
- Mechanism: Involves Krebs cycle, oxidation of glucose, fatty acids and amino acids in presence of oxygen. Produces 32 ATP molecules per glucose molecule.
15
Q
What are some physiological changes during exercise?
A
- Increase in CO2 and lactic acid
- Increase in muscle movement
- Increase return of blood flow to the heart
